India’s oldest nuclear power plant has resumed full operations after an extensive modernisation programme, with the first two units of the Tarapur Atomic Power Station (TAPS) in Maharashtra reconnecting to the grid, according to World Nuclear News.

Tarapur Units 1 and 2, boiling water reactors (BWRs) commissioned in 1969 as India’s first commercial nuclear power facility, had been offline since 2020 for a comprehensive refurbishment programme undertaken by Nuclear Power Corporation of India Limited (NPCIL). The reactors, originally built by General Electric and initially rated at 200 MW each before being reduced to 160MW gross capacity, had previously undergone refurbishment in 2005-06.

The Atomic Energy Regulatory Board (AERB) approved the restart and continued operation of Unit 2 on May 7 following the completion of the upgrade works. The regulator said the refurbishment involved replacing the reactor coolant recirculation piping system with advanced corrosion-resistant stainless-steel components, alongside a series of safety enhancements.

According to the AERB, the upgrades included the installation of a filtered containment venting system and an alternative cooling water system. Detailed inspections of critical reactor components, including reactor pressure vessel welds, were also conducted to assess ageing and determine the plant’s remaining operational life.

The regulator concluded that the reactor remains fit for continued service under standard maintenance and monitoring programmes and granted permission for Unit 2 to operate for another decade. Unit 1 received approval to restart in December last year and is currently operating at its full rated output of 160MW.

NPCIL described the return of both reactors to service as a significant achievement for India’s nuclear energy sector, stating that the project demonstrated the country’s engineering capabilities, operational expertise and commitment to safety. The company said the two units have played a key role in supporting India’s energy security for more than 50 years by providing reliable low-carbon electricity.

The Tarapur site also hosts two indigenous pressurised heavy water reactors, Units 3 and 4, which entered commercial operation in 2005 and 2006, respectively. The location has additionally been identified for the proposed deployment of India-designed small modular reactors, including the 200-MW BSMR-200 and the 55-MW SMR-55.